That appears to have the same switch that I have on my RoughStack. Now, I don't know if this is ok...but I've actually removed and submerged my switch in 99.9% iso alcohol and ultrasonic'd it for a couple mins, then blew out with compressed air and it worked like a CHARM for intermittent pushes. To remove your switch just unscrew the small nut at the base of your button (if necessary).
If your mini vapestack is similar it may look like this inside:
http://www.e-cigarette-forum.com/fo...-roughstack-switch-battery-connector-cap.html I just toss the whole switch and board assembly into the alcohol.
Also, I clean all the connections with alcohol often. The + and - connections internally and on the battery, the inside and outside of the 510 connector...those few things make it work like new!
Good luck!
ice